Patients who had robot-assisted prostate surgery before the procedure became widespread were significantly more likely to suffer complications, according to a new study published online by the Journal of the American Medical Association Wednesday.

The article, from a group at UC San Diego, analyzed the hospital-discharge records of 401,325 American men who underwent radical prostatectomies for prostate cancer from 2003 to 2009.

Researchers found that in 2005, the year before use of the da Vinci robotic surgery system became more common at teaching hospitals across the nation, the odds of complications were twice as high for the new technique when compared to traditional “open” procedures, which require a much larger incision and longer recovery times.

The pattern was similar, though less pronounced, for nonteaching hospitals in 2007, the year before robot-assisted prostatectomy became widespread in the United States, according to the UC San Diego analysis.

While the gap in complication rates only lasted for about one year, the paper’s authors said their analysis shows a need for better training and monitoring of results when new medical technologies move from the lab to the hospital.

“The robot itself is not inherently unsafe. It is a very sophisticated piece of medical equipment. The problem we face within the medical community is that we don’t have a standardized system by which new medical devices are introduced into broad community practice,” said Dr. J. Kellogg Parsons, the paper’s lead author and a urologist with the UC San Diego Health System and Moores Cancer Center.

Kellogg said a similar trend occurred when minimally invasive techniques were introduced for gallbladder and kidney surgeries in the early 1990s.

Intuitive and the urologists questioned the validity of the analysis by Parsons and his team.

Because there was no specific billing code for robot-assisted radical prostatectomy until 2008, the analysis counted all cases performed with a laparoscope as da Vinci cases. While the thin surgical instrument is also used to do minimally invasive prostate surgery, it is a different kind of tool — handled mechanically by a doctor squeezing scissor-like handles rather than moving da Vinci’s digital joysticks.

“The authors used incomplete and inaccurate procedure coding analysis that led to flawed conclusions,” Intuitive said in a statement.

“This data set is contaminated with pure laparoscopic prostatectomy cases and fails to adjust for important confounders such as surgeon experience and disease characteristics,” said the journal commentary, which was penned by Mohamad Allaf and Alan Partin at Johns Hopkins.

Parsons said he and his team are confident in their conclusions. He said few surgeons were performing pure laparoscopic prostatectomies in the years of data analyzed, and data showed that 98 percent of the procedures reported in 2009 used the new robotic code introduced in 2008.

And, he added, including true laparoscopic cases in the analysis would only make robotic surgeries look better.

“Inclusion of “pure laparoscopic cases” in the analysis would most likely have diluted the statistical signal from robotic surgery and led to a decrease in the observed difference between robotic and open surgery,” Parsons said.

The debate comes amid an increasing focus on the potential dangers of introducing new medical technology into practice.

The U.S. Food and Drug Administration received an increased number of problem reports on da Vinci systems in 2013, including some of “device-associated death, serious injuries and malfunctions” according to its website. The regulator continues to investigate those reports and to survey surgeons who use the technology to better understand its use in the industry.

Last year, the FDA updated a report that calls for strengthening the “surveillance” programs used to spot problems with new devices after they are introduced.

The report urges modernizing event reporting for new devices so that it is easier to quickly spot patient harm and take action.

Marilyn Neder Flack, executive director of the Association for the Advancement of Medical Instrumentation Foundation and senior vice president of that organization’s patient safety initiatives, said studies like the one performed by the Parsons team bolster the growing call for better training on new devices, whether they are new in the industry or just an update of an existing technology.

“This is an ongoing, day-to-day problem in hospitals,” Flack said.

Intuitive runs its own training program for the da Vinci systems it sells. The program has come under fire in recent years for not being rigorous enough, with some surgeons and lawyers saying that, in some cases, it includes only seven hours of hands-on training over a weekend before surgeons. After that, surgeons can do two to five operations that are “proctored” by another doctor before they can start operating on their own.

Flack said that it may take many more cases for a surgeon to become truly proficient with the technology. Uptake rates vary by surgeon, she said.

“Intuitive, I believe, does have good training. The training itself is fine. It’s getting the doctors to take the training that is the issue here. Professional societies have got to take a stand on this, as do hospitals,” Flack said.

Dr. David Chang, director of outcomes research at UC San Diego School of Medicine and a member of the group of researchers that wrote the JAMA Surgery report, said patients should be aware of how many procedures their doctor has done when he or she recommends treatment with a new technology.

“The question to ask is not whether or not the technology works but how many of these have you personally done?” Chang said.